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HelpOrder Code LABAAUCD Amino Acids, Urea Cycle Disorders Panel, Plasma
Additional Codes
Mayo Test Code: AAUCD
EPIC Order Code: LABAAUCD
Reporting Name
Amino Acid, Urea Cycle Panel, PUseful For
Follow-up of patients with urea cycle disorders
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
PlasmaOrdering Guidance
Body fluids are not acceptable specimens for this test.
For testing on urine specimens, order AAPD / Amino Acids, Quantitative, Random, Urine.
For testing on spinal fluid specimens, order AACSF / Amino Acids, Quantitative, Spinal Fluid.
Necessary Information
1. Patient's age is required.
2. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.
Specimen Required
Patient Preparation: Patient should fast overnight (4 hours minimum); infants should have specimen collected before next feeding (2-3 hours without total parenteral nutrition if possible).
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Green top (sodium heparin)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Collect specimen and place on wet ice. Note: Thrombin-activated tubes should not be used for collection.
2. Centrifuge immediately or within 4 hours of collection if the specimen is kept at refrigerated temperature.
3. Being careful to ensure that no buffy coat is transferred, aliquot plasma into a plastic vial and freeze.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma | Frozen | 14 days |
Reference Values
Glutamine
<24 months: 356-857 nmol/mL
2-17 years: 353-790 nmol/mL
≥18 years: 447-774 nmol/mL
Ornithine
<24 months: 32-171 nmol/mL
2-17 years: 32-148 nmol/mL
≥18 years: 39-154 nmol/mL
Citrulline
<24 months: 8-42 nmol/mL
2-17 years: 12-44 nmol/mL
≥18 years: 18-57 nmol/mL
Arginine
<24 months: 28-164 nmol/mL
2-17 years: 28-156 nmol/mL
≥18 years: 45-144 nmol/mL
Argininosuccinic Acid
<5 nmol/mL
Reference value applies to all ages.
Day(s) Performed
Monday through Friday
CPT Code Information
82136
Method Description
Quantitative analysis of amino acids is performed by liquid chromatography tandem mass spectrometry. Patient samples are combined with isotopically labeled internal standard. Following protein precipitation, the supernatant is subjected to hydrophilic-interaction liquid chromatography for the separation of isomers with MS/MS detection of the underivatized amino acids.(Unpublished Mayo method)
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Genetics Test Information
Urea cycle disorders are a group of inherited disorders of nitrogen detoxification that result from defects in any of the enzymes involved in the urea cycle.
Disruption of the urea cycle can result in the accumulation of ammonia, which is toxic to the nervous system.